This study provides preliminary data for establishing
a ‘baseline-level’ of aneuploidy in the female germ
cells of two Italian autochthonous cattle (Bos taurus)
breeds, the Podolian and Maremmana, by FISH
applied on MII metaphase oocytes with the
corresponding first polar body (PB). Painting probes
for chromosomes Xcen and 5 were obtained by
microdissection and DOP-PCR. COCs from 15
Podolian and 11 Maremmana cows were matured in
vitro in TCM199 with 20% FCS, 0.5 ìg/ml FSH and
5 ìg/ml LH. After denudation, the oocytes were
individually fixed on slides with 1:1 Carnoy fixative.
Totally, out of 396 COCs selected for IVM, 305
reached the MII stage (77.0%); of these, 31 (10.2%)
were unreduced. Out of 274 MII reduced oocytes, 200
(73.0%) had visible PB, therefore were FISH analyzed.
Aneuploid oocytes were 4 out of 200 (2.0%), 3
were nullisomic and 1 disomic, all for chromosome 5.
Premature separation of sister chromatids (PSSC) was
found only in two oocytes (1%), one for each breed.
At breed level, out of 100 oocytes examined in the
Podolian, two were found to be nullisomic and one
disomic, all for chromosome 5; out of 100 oocytes
examined in the Maremmana, only one oocyte was
found to be nullisomic for chromosome 5. Interestingly,
chromosome X was never involved in aneuploidy.
Totally, the two breeds showed different
aneuploidy rates: 3% (Podolian) vs 1% (Maremmana).
These preliminary results, together with
previous results obtained on the Friesian and Brown
breeds, suggest that ‘interbreed’ differences can be
found among the various domestic breeds. This aspect
is worth to be further investigated.

This study provides preliminary data for establishing
a ‘baseline-level’ of aneuploidy in the female germ
cells of two Italian autochthonous cattle (Bos taurus)
breeds, the Podolian and Maremmana, by FISH
applied on MII metaphase oocytes with the
corresponding first polar body (PB). Painting probes
for chromosomes Xcen and 5 were obtained by
microdissection and DOP-PCR. COCs from 15
Podolian and 11 Maremmana cows were matured in
vitro in TCM199 with 20% FCS, 0.5 ìg/ml FSH and
5 ìg/ml LH. After denudation, the oocytes were
individually fixed on slides with 1:1 Carnoy fixative.
Totally, out of 396 COCs selected for IVM, 305
reached the MII stage (77.0%); of these, 31 (10.2%)
were unreduced. Out of 274 MII reduced oocytes, 200
(73.0%) had visible PB, therefore were FISH analyzed.
Aneuploid oocytes were 4 out of 200 (2.0%), 3
were nullisomic and 1 disomic, all for chromosome 5.
Premature separation of sister chromatids (PSSC) was
found only in two oocytes (1%), one for each breed.
At breed level, out of 100 oocytes examined in the
Podolian, two were found to be nullisomic and one
disomic, all for chromosome 5; out of 100 oocytes
examined in the Maremmana, only one oocyte was
found to be nullisomic for chromosome 5. Interestingly,
chromosome X was never involved in aneuploidy.
Totally, the two breeds showed different
aneuploidy rates: 3% (Podolian) vs 1% (Maremmana).
These preliminary results, together with
previous results obtained on the Friesian and Brown
breeds, suggest that ‘interbreed’ differences can be
found among the various domestic breeds. This aspect
is worth to be further investigated.